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bolts...
- Thread starter grolls
- Start date
grolls
Well-Known Forum User
Albrecht
Well-Known Forum User
Perfectly adequate for your intended use, I think? Not casting any doubt on your spec, but I doubt you are building a full race engine?
What you need to do is blueprint your engine. The OEM fasteners are quite adequate to cope on a road-power engine. It's when other things are wrong that the OEM fasteners fail....
Of course, I don't have any hi-po fasteners to sell to you, so I'm a little bit biased......
ben240z
Club Member
ARP do what they say on the tin.
However Albrecht,s point as ever is valid. Why spend ££££££££££££ just to have a brand named part when the OEM was designed to do the job in hand.
The reason I went for the ARP was cos I knew that the engine was going to be running hard, at high revs, with high compression and regular strip downs.
You pays your money and takes your choice
However Albrecht,s point as ever is valid. Why spend ££££££££££££ just to have a brand named part when the OEM was designed to do the job in hand.
The reason I went for the ARP was cos I knew that the engine was going to be running hard, at high revs, with high compression and regular strip downs.
You pays your money and takes your choice
johnymd
Club Member
I have always thought that ARP studs and bolts are "better" than standard, I was hoping someone cleverer than me could quantify this and explain why.
When you build an engine, or even a car for that matter, it would be nice to select the best of everything. Unfortunately, being a person of limited budget, I have to be selective as to where the money is spent by spending it where it is most needed and economizing where it is not.
Another question that springs to mind is can ARP studs be reused?, and I guess I need to ask the same question of standard Studs.
When you build an engine, or even a car for that matter, it would be nice to select the best of everything. Unfortunately, being a person of limited budget, I have to be selective as to where the money is spent by spending it where it is most needed and economizing where it is not.
Another question that springs to mind is can ARP studs be reused?, and I guess I need to ask the same question of standard Studs.
ben240z
Club Member
I have re used the arp head studs and main cap studs many times. They are readily available from good old USA.
I think they are used in race engines because they are less likely to stretch and torque down more evenly with in reason time after time(I will most likely be shot down in flames for that statement) They are also lighter than the OEM items
My engine comes apart every 500 miles for a check over and further tweeking because of what I am doing with it. I even re use the head gaskets!!!!!!
I have to admit that if I was building a nice road engine that was going to be used on track days and pushing some high compresion and power then I would probably use ARP studs in that but building a nice engine to go in a road car that was just for cruising around our glorious roads then I would save the money for something else and use the OEM bolts( they hold together on turbo engines)
Hope this answers your questions but if not then give me a ring on 07766547871 or 0196350197. I am always willing to help.
Ben
Grolls, I've only ever had OEM in my motor if that helps. Never had a problem, but then your OEM crank broke - how unlucky is that?
Mr.F
Inactive
To quote ARP themselves:
"The process begins right at the mill, where ARP orders
only premium grade materials including several proprietary
alloys. The ever-popular 8740 chrome moly steel, for
example, comes from the mill in four distinct grades. The
lowest is “commercial,” which is followed by “aircraft quality.”
ARP uses only the top two grades (SDF and CHQ), which
cost twice as much, but provide the foundation for defect-free
fasteners. These materials come in bar stock (for studs) and
huge coils (for bolts).
Transforming raw material into a fastener begins with
“hot” and “cold” heading processes. Material is fed into powerful
devices and cold forged, or induction-heated and formed under tons of pressure.
Following the basic shaping, material is heat-treated to
desired levels. This crucial process is done entirely in-house
to assure total quality control. ARP uses special vertical racks
to hold each piece individually and assure complete 360° penetration.
This is far superior to commonly-used methods of
dumping items into a large bin and batch-treating.
Studs are centerless ground to guarantee concentricity.
The thread rolling operation (to MIL-S-8879A specs) is done
after heat-treat, which accounts for a fatigue strength up to
ten times higher than fasteners which are threaded prior to
heat-treat.
ARP manufactures nuts in a multi-step process that begins
with raw material being fed into a giant forming device that
“blanks” the hex and 12-point nuts and continues with highly
sophisticated automated threading equipment tapping each
nut with an accuracy of .001˝ (which is five times higher than
the aerospace standard). This ensures an exceptionally close tolerance
fit between the bolt/stud and nut.
Metal finishing is also performed in-house at ARP.
Operations include black oxide coating of chrome moly or polishing stainless steel to a brilliant lustre.
Some of the tests that ARP personnel perform on an ongoing
basis include proof loading (using a 120,000 lb. capability tensile
machine), fatigue cycle (Amsler) and hardness (Rockwell).
Visual inspections include use of an Optical Comparator (to
check thread root contour, etc.), fixtured micrometers and
microscopic grain flow analysis. The computer-controlled
fatigue cycle testers allow ARP to take fasteners to a failure
point in millions of cycles – as opposed to the aerospace norm
of 65,000 average to 130,000 cycles maximum. This allows
ARP engineers to verify the design specifications of each
fastener, and prove its ability to provide superior long-term
service."
And yes, I do sell them and have used them personally...
"The process begins right at the mill, where ARP orders
only premium grade materials including several proprietary
alloys. The ever-popular 8740 chrome moly steel, for
example, comes from the mill in four distinct grades. The
lowest is “commercial,” which is followed by “aircraft quality.”
ARP uses only the top two grades (SDF and CHQ), which
cost twice as much, but provide the foundation for defect-free
fasteners. These materials come in bar stock (for studs) and
huge coils (for bolts).
Transforming raw material into a fastener begins with
“hot” and “cold” heading processes. Material is fed into powerful
devices and cold forged, or induction-heated and formed under tons of pressure.
Following the basic shaping, material is heat-treated to
desired levels. This crucial process is done entirely in-house
to assure total quality control. ARP uses special vertical racks
to hold each piece individually and assure complete 360° penetration.
This is far superior to commonly-used methods of
dumping items into a large bin and batch-treating.
Studs are centerless ground to guarantee concentricity.
The thread rolling operation (to MIL-S-8879A specs) is done
after heat-treat, which accounts for a fatigue strength up to
ten times higher than fasteners which are threaded prior to
heat-treat.
ARP manufactures nuts in a multi-step process that begins
with raw material being fed into a giant forming device that
“blanks” the hex and 12-point nuts and continues with highly
sophisticated automated threading equipment tapping each
nut with an accuracy of .001˝ (which is five times higher than
the aerospace standard). This ensures an exceptionally close tolerance
fit between the bolt/stud and nut.
Metal finishing is also performed in-house at ARP.
Operations include black oxide coating of chrome moly or polishing stainless steel to a brilliant lustre.
Some of the tests that ARP personnel perform on an ongoing
basis include proof loading (using a 120,000 lb. capability tensile
machine), fatigue cycle (Amsler) and hardness (Rockwell).
Visual inspections include use of an Optical Comparator (to
check thread root contour, etc.), fixtured micrometers and
microscopic grain flow analysis. The computer-controlled
fatigue cycle testers allow ARP to take fasteners to a failure
point in millions of cycles – as opposed to the aerospace norm
of 65,000 average to 130,000 cycles maximum. This allows
ARP engineers to verify the design specifications of each
fastener, and prove its ability to provide superior long-term
service."
And yes, I do sell them and have used them personally...
grolls
Well-Known Forum User
And probably the same ones that came with the car
life can be tough.......
cars can be a bitch
SeanDezart
Well-Known Forum User
Grolls - what does your engine producer say ? Yours was more than just a normal road engine.
I have ARPs in mine.
I have ARPs in mine.
grolls
Well-Known Forum User
If he was still in business i'd ask him....
....but may attempt a call today....Thanks for the comments all btw...
And probably the same ones that came with the car
Don't knock it Pete, my engine is the same one that came with the car too in '73. It was rebuilt and modified at the turn of the century and still a beauty
.So how many people on this Forum have had a OEM bolt break in a modified (or otherwise engine)? I would be interested to know and it would help Grolls with his decision too.
Ian Patmore
Well-Known Forum User
Grolls,
Go OEM, my engine has. My engine builder has had problems with the ARP ones, and won't use them.
Go OEM, my engine has. My engine builder has had problems with the ARP ones, and won't use them.